A Unique Material Identifier (UMID) is a signature that is used to identify media materials, such as audio and video clips. The main purpose of the UMID is to enable media creators, editors, and others to identify and locate material in storage systems, and to provide constant identification throughout production, archival storage, transmission, and dissemination of media. Ideally, UMIDs are generated at the point of material origination without reference to a central resource. The value of a UMID stems from its guaranteed one-to-one correspondence with a particular item of media source material. However, certain points of media material origination do not generate a UMID, with the consequence that UMID generation takes place at a subsequent stage in the handling of the media. In such circumstances, a given item of material may be assigned more than one UMID when imported by different devices or applications. This can produce confusion, and cause problems with media editing, media management, and archiving applications that rely on the uniqueness of a UMID.